Method and apparatus for managing connection path failure between data centers for cloud computing

ABSTRACT

A first cloud computing data center and a second cloud computing data center are connected through a provider backbone bridge network (PBBN), and a plurality of working connection paths and protection connection paths are formed between end points between the first cloud computing data center and the second cloud computing data center and between end points within a cloud computing data center through the PBBN. When a failure occurs in the working connection path, the working connection path is switched to a corresponding protection connection path.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2012-0071134 filed in the Korean IntellectualProperty Office on Jun. 29, 2012, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a method and apparatus for managing aconnection path failure. More particularly, the present inventionrelates to a method and apparatus for managing a connection path failurebetween cloud computing data centers.

(b) Description of the Related Art

Cloud computing is a kind of distributed computing environment of aservice form that moves an individually existing plurality of computingresources to one area, for example, a cloud area, which is an Internetenvironment having a computing function, and that enables a user to usea necessary computing resource by connecting to the Internet at any timeand place using a terminal and that selectively performs accounting. Inthe cloud area, a plurality of physical or logical servers exist as aresource, and this is referred to as a cloud resource. The cloudresources are connected to each other through a network.

For an efficient cloud computing service, a data center for managing acloud resource is requested. Nowadays, in order to efficiently manage alarge-scale resource, server virtualization technology in which a datacenter makes a host to a virtual machine (VM) and allocates the host toa server is applied. By server virtualization, one server supportsseveral hundred VMs or more. When a VM of the host is allocated to anoverloaded server, VM migration that reallocates the VM to a server withless load should occur between servers within a data center or betweendata centers through a core network. In this case, a large capacitypacket such as a VM image file should be transmitted, and acommunication delay time of a server should not deviate from anestimated range and not cause damage.

Further, nowadays, because data traffic between servers has rapidlyincreased, high speed networking construction and management betweencloud computing data centers is necessary. Particularly, when a failureoccurs in a connection path for packet transmission, high speednetworking is not performed and thus a replacement processing of failureoccurrence is requested.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a method andapparatus for managing a connection path failure having advantages ofefficiently processing a failure occurring in a connection path forvirtual machine migration and packet transmission between data centersin cloud computing.

An exemplary embodiment of the present invention provides a method ofmanaging a connection path failure, wherein a first cloud computing datacenter and a second cloud computing data center are connected through aprovider backbone bridge network (PBBN), the method including: forming aplurality of working connection paths and protection connection pathsbetween end points between the first cloud computing data center and thesecond cloud computing data center through the PBBN and between endpoints within the cloud computing data center; exchanging a test messagebetween the end points; determining that a failure has occurred at acorresponding working connection path when the test message is notreceived at a random end point; and switching the working connectionpath in which a failure has occurred to the protection connection path.

The data center may include a provider bridge (PB) device that isconnected to the PBBN, and a switch that is connected to a plurality ofservers including a plurality of virtual machines (VM). The forming of aplurality of working connection paths may include forming a connectionpath including the working connection path and the protection connectionpath based on a first virtual local access network (VLAN) between the VMand the switch, a second VLAN of the PB device, and a third VLAN and afourth VLAN (I-SID) of a provider edge bridge (PEB) and a provider corebridge (PCB) that are included in the PBBN. Ethernet switched path (ESP)information including a destination address, a source address, and aVLAN identifier may be allocated to the connection path.

At a PEB ingress point, by frame-encapsulating VLAN identifiers of thethird VLAN and the fourth VLAN I-SID, a connection path may be formed,and at a PEB egress point, by decapsulating VLAN identifiers of thethird VLAN and the fourth VLAN I-SID, a connection path for VM migrationmay be set.

The forming of a plurality of working connection paths may furtherinclude setting operation and maintenance (OAM) attributes includinggeneration of a maintenance domain (MD), a maintenance association (MA),and a maintenance end point (ME) to the connection paths.

The switching of the working connection path may include transmitting,by the random end point, a message representing that a workingconnection path is switched to the protection connection path, to anetwork management system (NMS) of a corresponding data center.

Another embodiment of the present invention provides an apparatus thatmanages a connection path failure at a random end point that ispositioned within a cloud computing data center, wherein the cloudcomputing data center is connected to another data center through aPBBN, and a plurality of working connection paths and protectionconnection paths are formed between end points within the cloudcomputing data center or between end points of the other data centerthrough the PBBN. The apparatus includes: a message exchange unit thatexchanges a test message with an end point that is connected to acorresponding working connection path through the working connectionpath; a failure generation check unit that determines that a failure hasoccurred in a corresponding working connection path when the testmessage is not received from the connected end point; and a pathswitching unit that switches the working connection path in which afailure has occurred to a protection connection path.

The failure generation check unit may determine that a failure hasoccurred in the working connection path when the test message is notreceived within a preset time or when a kind of a frame of the receivedmessage does not correspond to a kind of the test message.

The path switching unit may notify a management system of the cloudcomputing data center of a message representing that a path was switchedfrom the working connection path to the protection connection path.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a structure of a cloud computing datacenter according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram illustrating a connection path of a providerbackbone bridge network based on VLAN ID mapping of Table 1.

FIG. 3 is a diagram illustrating connection paths according to anexemplary embodiment of the present invention.

FIG. 4 is a diagram illustrating a structure of a data frame accordingto an exemplary embodiment of the present invention.

FIG. 5 is a flowchart illustrating a method of managing a data centerconnection path according to an exemplary embodiment of the presentinvention.

FIG. 6 is a block diagram illustrating a configuration of a connectionpath failure management apparatus according to an exemplary embodimentof the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, only certain exemplaryembodiments of the present invention have been shown and described,simply by way of illustration. As those skilled in the art wouldrealize, the described embodiments may be modified in various differentways, all without departing from the spirit or scope of the presentinvention.

Accordingly, the drawings and description are to be regarded asillustrative in nature and not restrictive. Like reference numeralsdesignate like elements throughout the specification.

In addition, in the specification and claims, unless explicitlydescribed to the contrary, the word “comprise” and variations such as“comprises” or “comprising” will be understood to imply the inclusion ofstated elements but not the exclusion of any other elements.

Hereinafter, a method and apparatus for managing a connection pathfailure between cloud computing data centers according to an exemplaryembodiment of the present invention will be described.

FIG. 1 is a diagram illustrating a structure of a cloud computing datacenter according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a cloud computing data center 1 (hereinafter, forbetter comprehension and ease of description, referred to as a “datacenter”) according to an exemplary embodiment of the present inventionforms a provider backborn bridge network (PBBN) with provider corebridges (PCB) 10 and 11 that provide a provider core bridging functionand provider edge bridges (PEB) 12 and 13 that provide a provider edgebridging function. These bridges 10, 11, 12, and 13 have, for example,100/400/1000 ethernet interface speed.

The data center 1 includes a network management system (NMS) 20, switchdevices, i.e., top of rack (ToR) switches 31, 32, 33, and 34, andprovider bridge (PB) devices 41 and 42, and the ToR switches areconnected to a plurality of servers 50, respectively, and each serverincludes at least one virtual machine (VM) 60.

The PBs 41 and 42 provide a provider bridging function and perform atraffic line concentration function between the ToR switches 31, 32, 33,and 34. The PBs 41 and 42 have an extension field (e.g., VLAN 31 and 32extension fields) necessary for identifying many VMs.

The ToR switches 31, 32, 33, and 34 process traffic of a plurality ofservers 50 and a plurality of VMs 60, are access-class switches, andprocess a plurality of servers and a plurality of VM traffic. Serversare mounted in a rack, form a server group, and are connected through aToR switch. Each server supports the VM 60 and includes a VM virtualswitch for connecting VMs.

The NMS 20 performs control and management functions within the datacenter, and transmits/receives a control message for setting andmanaging a connection path to the ToR switches 31-34, the PB devices 41and 42, and the PEBs 12 and 13. The NMS 20 includes an NMS provisioningmanager, and manages cloud computing data center connection paths by theNMS provisioning manager.

The data center 1 having such a structure may be connected to anotherdata center through the PBBN.

The NMS 20 of the data center 1 performs setting and management of aconnection path, and sets a connection path through message exchangewith a management agent (not shown) within the ToR switch, the PBdevice, and the PEB.

The connection path is set based on a virtual local access network(VLAN), and connection paths are set based on a C-VLAN between the VM 60and the ToR switches 31-34, an S-VLAN of the PB devices 41 and 42, and abackbone service instance ID (I-SID) and a B-VLAN of the PEB and thePCB. Ethernet switched path (ESP) information including a destinationaddress (DA), a source address (SA), and a VID, which is a VLANidentifier, is allocated to each VLAN. Connection paths based on eachVLAN are mapped as shown in Table 1.

TABLE 1 C-VID S-VID I-SID B-VID 42 3 X 32 33 61 41 4 62 51 31 52

Table 1 is an example illustrating identifier mapping of connectionpaths based on a VLAN, a C-VID is an identifier of a C-VLAN that is setto a VM and a ToR switch, an S-VID is an identifier of an S-VLAN that isset to a PB, and an I-SID and a B-VID are identifiers of an I-SID and aB-VLAN that are set to a PEB and a PCB, respectively, of a providerbackbone network.

At a PEB ingress point, by frame-encapsulating the C-VID and the S-VID,a connection path is formed, and at a PEB egress point, by decapsulatingthe C-VID and the S-VID, a connection path for VM migration is set.

A connection path of a provider backbone bridge network according toVLAN ID mapping according to Table 1 is displayed in FIG. 2.

FIG. 2 is a diagram illustrating a connection path of a providerbackbone bridge network based on VLAN ID mapping of Table 1.

An I-SID and a B-VLAN that are formed in a provider backbone bridge edge(PBB), which is a PEB and a PCE constituting a provider backbone bridgenetwork (PBBN), have an identifier B-VIDx.

Specifically, referring to Table 1, a PBBN connection path B-VIDx isformed with two PBB connection paths having backbone service identifiersI-SID3 and I-SID4, and I-SID3 is connected to a PB network havingS-VID42, S-VID32, and S-VID33 VLANs. An I-SID4 PBB connection path isconnected to a PB network having S-VID31 and S-VID41 VLANs, S-VID31 andS-VID41 PB networks are logically mapped to C-VID51, C-VID52, C-VID61,and C-VID62 VLAN IDs, respectively, and connection path setting and VMmigration between data centers are performed.

As illustrated above, connection paths that are connected to anotherdata center are formed through the PBBN based on VLANs. Connection pathsthat are connected to a data center through a PBBN for protectionswitching include a working connection path, which is a traffic pathbetween end points, and a protection connection path, which is anothertraffic path between end points, for protecting the working connectionpath.

FIG. 3 is a diagram illustrating connection paths according to anexemplary embodiment of the present invention.

As shown in FIG. 3, connection paths according to an exemplaryembodiment of the present invention include an ESP1, which is aconnection path of a PEB2 13 direction in a PEB1 12, an ESP2, which is aconnection path of the PEB1 12 direction in the PEB2 13, an ESP3, whichis a connection path of the PEB2 13 direction in the PEB1 12, and anESP4, which is a connection path of the PEB1 12 direction in the PEB213. The ESP1 includes DA2, SA1, and VID1, the ESP2 includes DA1, SA2,and VID2, the ESP3 includes DA4, SA3, and VID3, and the ESP4 includesDA3, SA4, and VID4.

Connection paths for protection switching are Traffic EngineeringService Instances (TESI), and include TESI1, which is a workingconnection path of a PEB2 13 direction in the PEB1 12, TESI2, which is aworking connection path of a PEB2 13 direction in the PEB2 13, TESI3,which is a protection connection path of the PEB2 13 direction in thePEB1 12, and TESI4, which is a protection connection path of the PEB1 12direction in the PEB2 13.

TESI1={ESP1, ESP2}, TESI2={ESP2, ESP1}, TESI3={ESP3, ESP4}, andTESI4={ESP4, ESP3} are satisfied.

In a connection path that is formed in this way, a connection testmessage for checking a state of each connection path is exchangedbetween the PEB1 and the PEB2, which are end points of the workingconnection path and the protection connection path. When a failure isfound in a connection test, the working connection path is switched to aprotection connection path, and path switching may be performed within atime of, for example, 50 ms.

A data frame format according to an exemplary embodiment of the presentinvention has a structure of FIG. 4. FIG. 4 is a diagram illustrating astructure of a data frame according to an exemplary embodiment of thepresent invention.

As shown in FIG. 4, the VM 60 and the ToR switches 31-34 as an L2 dataframe format that is applied to an exemplary embodiment of the presentinvention use a data frame having a first frame format (e.g., 802.1Qstandard frame format), the PBs 41 and 42 use a data frame having asecond frame format (e.g., 802.1ad standard frame format), and the PEBs12 and 13 and the PCBs 10 and 11 use a data frame having a third frameformat (e.g., 802.1ah standard frame format).

Hereinafter, a method of managing a connection path failure will bedescribed.

FIG. 5 is a flowchart illustrating a method of managing a data centerconnection path according to an exemplary embodiment of the presentinvention.

In order to set a connection path to a management target, i.e., ToRswitches 31-34, PB devices 41 and 42, and PEBs 12 and 13, the cloudcomputing data center 1 sets a VLAN through a management agent (notshown) that is included in each management target. Specifically, aC-VLAN is set between the VM 60 and the ToR switches 31-34, an S-VLAN ofthe PB devices 41 and 42 is set, and an I-VLAN and a B-VLAN are set tothe PEB and the PCB, respectively (S100).

Each VLAN sets ESP information including DA, SA, and VID (S120).Further, a working connection path, which is a traffic path between endpoints, and a protection connection path, which is another traffic pathbetween end points for protecting the working connection path, are set(S130 and S140). The working connection path and the protectionconnection path include ESP connection information based on ESPinformation.

For operation management and maintenance that monitor and process afailure in connection paths, operation and maintenance (OAM) attributesincluding generation of a maintenance domain (MD), a maintenanceassociation (MA), and a maintenance end point (ME) are set (S150). Whenthe connection path and the OAM attribute are set, a continuity checkmessage (CCM) is periodically exchanged between connection pathmaintenance end points (MEP) of connection paths (S160).

Each end point checks whether a CCM message is received within apredetermined time (S170) and each end point determines frameinformation of a message that is received within a predetermined time,and if a frame kind is a CCM, each end point determines a next CCMmessage.

If a CCM message is not received within a predetermined time or if frameinformation of the received message is not a CCM, it is determined thata connection path failure occurs, and thus the each end point transmitsa connection path failure message to the NMS 20 (S180).

The end point that determines that a connection path failure hasoccurred checks whether a state of a preset protection connection pathis good (S190), and if a failure does not exist in the protectionconnection path, each end point performs path switching to theprotection connection path (S200). Thereafter, after path switching tothe protection connection path is performed, a corresponding end pointtransmits a path switching message that notifies the NMS 20 of pathswitching (S210).

FIG. 6 is a block diagram illustrating a configuration of a connectionpath failure management apparatus according to an exemplary embodimentof the present invention.

A connection path failure management apparatus 100 according to anexemplary embodiment of the present invention include a message exchangeunit 110, a failure generation check unit 120, and a path switching unit130. The message exchange unit 110 exchanges a test message,particularly, a CCM, with an end point that is connected to acorresponding working connection path through a working connection path.

When a test message is not received from a connected end point or when aframe of a received message does not correspond with test message frameinformation, the failure generation check unit 120 determines that afailure has occurred in a corresponding working connection path.

The path switching unit 130 switches a working connection path in whicha failure has occurred to a protection connection path. The pathswitching unit 130 notifies that path switching was performed bytransmitting a path switching message to the NMS 120.

According to an exemplary embodiment of the present invention, aconnection path to another data center is set through a PBBN, and VMmigration is rapidly performed through the set connection path. Further,even in a case where a failure occurs at a connection path, switching toa protection connection path can be rapidly performed.

Also, in a cloud computing service, as a provider backbone bridge isformed between data centers, a connection path for packet transmissionis formed, and thus virtual machine migration and large capacity packettransmission between cloud computing data centers through the providerbackbone bridge are quickly performed.

Further, whether a failure occurs in a connection path in which aprovider backbone bridge is formed between data centers is monitored,and when a failure is found, by quickly switching the path to aprotection path, traffic damage is minimized, and thus cloud servicecontinuity and reliability can be provided.

An exemplary embodiment of the present invention may not only beembodied through the above-described apparatus and/or method, but mayalso be embodied through a program that executes a functioncorresponding to a configuration of the exemplary embodiment of thepresent invention or through a recording medium on which the program isrecorded, and can be easily embodied by a person of ordinary skill inthe art from a description of the foregoing exemplary embodiment.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A method of managing a connection path failure,wherein a first cloud computing data center and a second cloud computingdata center are connected through a provider backborn bridge network(PBBN), the method comprising: forming a plurality of working connectionpaths and protection connection paths between end points between thefirst cloud computing data center and the second cloud computing datacenter through the PBBN and between end points within the cloudcomputing data center; exchanging a test message between the end points;determining that a failure has occurred at a corresponding workingconnection path when the test message is not received at a random endpoint; and switching the working connection path in which a failure hasoccurred to the protection connection path.
 2. The method of claim 1,wherein the data center comprises a provider bridge (PB) device that isconnected to the PBBN and a switch that is connected to a plurality ofservers comprising a plurality of virtual machines (VM), and wherein theforming of a plurality of working connection paths comprises forming aconnection path comprising the working connection path and theprotection connection path based on a first virtual local access network(VLAN) between the VM and the switch, a second VLAN of the PB device,and a third VLAN and a fourth VLAN (I-SID) of a provider edge bridge(PEB) and a provider core bridge (PCB) that are included in the PBBN. 3.The method of claim 2, wherein ethernet switched path (ESP) informationcomprising a destination address, a source address, and a VLANidentifier (VI D) is allocated to the each VLAN.
 4. The method of claim2, wherein the forming of a plurality of working connection pathsfurther comprises setting operation and maintenance (OAM) attributescomprising generation of a maintenance domain (MD), a maintenanceassociation (MA), and a maintenance end point (ME) to the connectionpaths.
 5. The method of claim 1, wherein the switching of the workingconnection path comprises transmitting, by the random end point, amessage representing that a working connection path is switched to theprotection connection path, to a network management system (NMS) of acorresponding data center.
 6. The method of claim 1, wherein at theexchanging of a test message, the test message is formed with acontinuity check message (CCM) and is periodically exchanged between theend points.
 7. An apparatus that manages a connection path failure at arandom end point that is positioned within a cloud computing datacenter, wherein the cloud computing data center is connected to anotherdata center through a PBBN, and a plurality of working connection pathsand protection connection paths are formed between end points within thecloud computing data center or between end points of the other datacenter through the PBBN, the apparatus comprising: a message exchangeunit that exchanges a test message with an end point that is connectedto a corresponding working connection path through the workingconnection path; a failure generation check unit that determines that afailure has occurred in a corresponding working connection path when thetest message is not received from the connected end point; and a pathswitching unit that switches the working connection path in which afailure has occurred to the protection connection path.
 8. The apparatusof claim 7, wherein the failure generation check unit determines that afailure has occurred in the working connection path when the testmessage is not received within a preset time or when a kind of a frameof the received message does not correspond to a kind of the testmessage.
 9. The apparatus of claim 7, wherein the path switching unitnotifies a management system of the cloud computing data center of amessage representing that a path is switched from the working connectionpath to the protection connection path.
 10. The apparatus of claim 7,wherein the cloud computing data center comprises a PB device that isconnected to the PBBN and a switch that is connected to a plurality ofservers comprising a plurality of VMs, and a connection path comprisingthe working connection path and the protection connection path is formedbased on a first virtual local access network (VLAN) between the VM andthe switch, a second VLAN of the PB device, and a third VLAN and afourth VLAN (I-SID) of a provider edge bridge (PEB) and a provider corebridge (PCB) that are included in the PBBN.